Energy and its changes

Energy is the ability to do work, make something move or cause a change. A child needs energy to run, a car needs it to drive, a lamp needs it to shine. In nature the sources of energy are the Sun, wind, flowing water, coal, oil, gas and nuclear fuel. People and animals get energy from food, plants from sunlight. The Sun gives the most energy. Kinds of energy: mechanical (of a moving or lifted body: a runner, wind, a crane), heat (hot water, steam, fire), light (sunlight, lamp light) and electrical (electric current). In the past people carried loads themselves or with horses; now they use fuel and electricity.